Method and apparatus for withdrawing long-sized objects

ABSTRACT

A method and apparatus for continuously withdrawing an elongated product such as from a melt a fine wire is based on the rotating liquid medium spinning method. A layer of cooling liquid (14) is centrifugally formed on the inner peripheral surface of a rotational drum (13). Disposed inside the rotational drum (13) is a winding reel (19) having a rotating winding peripheral surface (18). A holder element (20) adapted to be magnetically attracted to the winding peripheral surface (18) is initially placed on the inner peripheral surface of the rotational drum (13). A molten material injected into the drum by a nozzle (16) is quenched for solidification in the cooling liquid (14) to form the product. Initially, the leading end emerging from the nozzle rides over the holder element (20) which then carries the leading end onto the winding peripheral surface (18) and holds it thereon by magnetic attraction. The product (17) is then wound on the winding peripheral surface (18) with its portion fixed by the holder element (20 ) serving as the winding starting end.

TECHNICAL FIELD

This invention relates to a method and apparatus for withdrawinglong-sized or elongated objects, particularly a method and apparatus bywhich a fine metal wire, for example, obtained by injecting molten metalthrough a nozzle and quenching it for solidification, is withdrawn bywinding the wire.

BACKGROUND ART

It is known to melt a metal or alloy and inject it as a fine stream intoa rotating cooling liquid to thereby produce a fine wire. This method iscalled "In-Rotating-Water Spinning Method" and is disclosed, forexample, in Japanese Patent Application Laying-Open No. 64948/1980.

In the "In-Rotating-Water Spinning Method" mentioned above, since a finewire can be obtained directly from a molten state, a fine wire of even ahard-to-work material can be easily obtained without requiring so muchenergy.

However, the "In-Rotating-Water Spinning Method" has presented theproblem that the fine wire centrifugally retained in the innerperipheral surface of the rotating drum, is very difficult to withdrawfrom the drum with a satisfactory efficiency. For example, to collectthe fine metal wire while continuously operating the rotating liquidmedium spinning apparatus, it is necessary to grip the end of the finewire or a portion thereof adjacent its end, but generally such grippinghas been difficult since it is moving at more than several meters persecond. Therefore, it has been common practice to take out the fine wireafter the rotation of the rotating drum is stopped.

On the other hand, it has generally been also difficult for the samereason to withdraw during operation such a long-sized object as a metaltape quenched for solidification by a roll quenching method.

In addition, a method which utilizes magnetic force for withdrawing anon-crystalline quenched tape while the latter is being continuouslyproduced is disclosed in Japanese Patent Application Laying-Open No.94453/1982, which suggests that the non-crystalline tape after beingsolidified, be continuously wound on a magnetized winding drum bymagnetically attracting said tape.

However, the aforesaid suggested method presents the problem that theelongated objects to be withdrawn are limited to magnetic materials.

SUMMARY OF THE INVENTION

Thus, the invention is intended to provide a method and apparatus whichmakes it possible to efficiently and reliably withdraw elongated objectsregardless of whether they are made of magnetic or non-magneticmaterials.

The method of withdrawing elongated objects according to the inventionuses a means in which, with an elongated object passing between awinding peripheral surface which is rotating magnetically and aeffective holder element magnetically attracted to said windingperipheral surface, the holder element is magnetically attracted to thewinding peripheral surface to thereby fix a portion of the elongatedobject to the winding peripheral surface, whereupon, with said fixedportion of the elongated object used as the winding starting end, theelongated object is wound on the winding peripheral surface.

In addition, to magnetically attract the holder element to the windingperipheral surface, as described above, either the holder element or thewinding peripheral surface is formed as a magnet and the other is formedof a ferromagnetic material.

In a method of withdrawing elongated objects according to a preferredembodiment of the invention, an elongated object placed on the innerperipheral surface of a rotating cylindrical drum and running with therotation of said drum, is wound on the winding peripheral surface of awinding reel having an axis which is disposed at a position within thedrum and off its center, said axis is extending in parallel to the axisof the drum and rotating in the same direction as the drum, forwithdrawing the elongated object. Such withdrawing method comprises asits first step, preparing a holder element adapted to be magneticallyattracted to the winding peripheral surface; at its second step, placingthe holder element on the inner peripheral surface of the rotatingcylindrical drum such that it is centrifugally retained thereon; as itsthird step, positioning the leading end of the elongated object on theholder element; as its fourth step, causing the holder element with theelongated object placed thereon to be attracted to the windingperipheral surface when the holder element passes close by the windingreel; as its fifth step, fixing a portion of the elongated object to thewinding peripheral surface by the holder element for winding theelongated object on the winding peripheral surface with said fixedportion of the elongated object used as a winding starting end.

In another preferred embodiment of said withdrawing method, the secondstep is performed at a position remote from a position close to thewinding reel and the third step is performed before the holder elementplaced in the second step reaches the position close to the windingreel, whereby, the holder element is prevented from being attracted tothe winding peripheral drum before it arrests the elongated object. Inaddition, from the same point of view, in the fourth step, the operationof moving the winding reel toward the inner peripheral surface of thedrum may be performed. Further, the magnetic force for attracting theholder element to the winding peripheral surface may be provided by anon-off controlled electromagnet and the latter may be turned on uponcompletion of the second and third steps.

An apparatus for withdrawing elongated objects according to theinvention comprises a path for conveying an elongated object, a windingmechanism disposed on one side of said conveying path and having arotating winding peripheral surface, and a holder element disposed onthe other side of the conveying path and adapted to be magneticallyattracted to the winding peripheral surface.

A preferred embodiment of such a withdrawing apparatus further comprisesmagnetic attraction control means for controlling the magnetic forcesuch that it is not until the elongated object passes between thewinding peripheral surface and the holder element, that the magneticforce is sufficient to attract the holder element to the windingperipheral surface. This magnetic attraction control means isimplemented by a means which reduces the distance between the windingperipheral surface and the holder element or, in the case where themagnetic force for attracting the holder element to the windingperipheral surface is provided by an electro-magnet, it is implementedby a switch means for on-off controlling the electromagnet.

Thus, according to the invention, a an elongated object to be withdrawnis taken up by the holder element adapted to be magnetically attractedto the winding peripheral surface, whereupon it is clamped between theholder element and the winding peripheral surface and fixed to thewinding peripheral surface. Therefore, the elongated object, whether itis a magnetic or non-magnetic material, can be reliably wound on thewinding peripheral surface for withdrawal. Even if the elongated objectis moving longitudinally thereof, the holder element can reliably arrestsaid object when attracted to the winding peripheral surface, thusmaking it possible to start the withdrawing operation without stoppingthe movement of the elongated object.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show a first embodiment of the invention, schematicallyillustrating an apparatus wherein a tape-like solidified object isobtained by the roll quenching method and is withdrawn.

FIGS. 3 to 5 show a second embodiment of the invention, schematicallyillustrating an apparatus wherein a wire-like solidified object isobtained the "In-Rotating-Water Spinning Method" and is withdrawn.

FIG. 6 shows a third embodiment of the invention, schematicallyillustrating an apparatus a cross-sectional view wherein a wire-likesolidified object is obtained by the "In-Rotating-Water Spinning Method"and is withdrawn.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND OF THE BESTMODE FOR CARRYING OUT THE INVENTION

FIGS. 1 and 2 show the invention as applied to the withdrawal of aquenched tape in the roll quenching method.

As shown in FIG. 1, a molten metal 1, such as a Cu-P alloy, is pouredonto the peripheral surface of a quenching roller 3 through a nozzle 2heated by a heater 2a. The quenching roller 3 is rotated in thedirection of arrow 4, and the molten metal 1 poured out through thenozzle 2 is quenched for solidification on the peripheral surface of thequenching roller 3. To withdraw this tape-like solidified body 5 as a anelongated object, the following arrangement is used.

The tape-like solidified body 5 is taken out in the direction of arrow6, and in this direction a winding drum 7 is disposed above the path oftravel of the tape-like solidified body 5 and a block 8 is disposedbelow said path. The winding drum 7 has a winding peripheral surface 9made of a ferromagnetic material, such as an iron-type material. Theblock 8 is made of non-magnetic material and is held as by a pantographmechanism 10, whereby it is vertically movable. A magnetically effectiveholder element 11 made of a permanent magnet is placed in a free stateon the block 8. The winding drum 7 is rotated in the direction of arrow12 at the same speed as that of the quenching roller 3.

Just after the front end of the tape-like solidified body 5 has passedbetween the winding peripheral surface 9 of the winding drum 7 and theholder element 11, the pantograph mechanism 10 is actuated to move theblock 8 toward the winding drum 7. In response thereto, the holderelement 11 is magnetically attracted to the winding peripheral surface9. At this time, the tape-like solidified body 5 is fixed to the windingperipheral surface 9 as it is carried on the holder element 11, and withthis fixed portion of the tape-like solidified body 5 serving as thewinding starting end, as shown in FIG. 2, the tape-like solidified body5 is wound on the winding drum 7.

FIGS. 3 to 5 show the invention as applied to the withdrawal of a finemetal wire produced by the "In-Rotating-Water Spinning Method".

For example, as shown in FIG. 3, a cooling liquid 14 is received in acylindrical rotational drum 13 and forms a liquid layer on the innerperipheral surface of the rotational drum 13 as the cooling liquid 14 iscentrifugally held when the rotational drum 13 is rotated in thedirection of arrow 15.

Disposed inside the rotational drum 13 is a nozzle 16 for injecting amolten metal into the cooling liquid 14. The nozzle 16 is provided withan unillustrated heater. Further, a pressurized gas is introduced intothe nozzle 16 through a conduit 16a. The molten metal injected from thenozzle 16 is quenched for solidification by the cooling liquid 14 toform a wire-like solidified body 17.

In addition, in this embodiment, the rotational drum 13 is made of anon-magnetic material, such as aluminum.

A winding reel 19 having a winding peripheral surface 18 is disposedinside the rotational drum 13 for withdrawing the wire-like or elongatedsolidified body 17. The winding reel 19 is disposed at a position offcenter of the rotational drum 13 and has an axis parallel with that ofthe drum 13. The winding reel 19 is rotated in the same direction as thedirection of rotation 15 of the drum 13. The winding peripheral surface18 has at least a portion thereof made of a ferromagnetic material, suchas an iron-type material.

In this embodiment, the winding reel 19 is movable from the solid lineposition to the phantom line position shown in FIG. 3, whereby thewinding peripheral surface 18 can be moved toward the inner peripheralsurface of the rotational drum 13.

A magnetically effective element 20 in the form of a permanent magnet isdisposed, for example in a free state, on the inner peripheral surfaceof the rotational drum 13 and is retained on the inner peripheralsurface of the drum 13 by the centrifugal force produced with therotation of the rotational drum 13.

To produce the fine metal wire, that is, wire-like solidified body 17and withdraw said wire-like solidified body 17, in the initial stage, asshown in FIG. 3, the winding reel 19 is rotated in the direction ofarrow 21 at the same peripheral speed as that of the rotational drum 13and, as shown in solid lines, is disposed at a position relativelyremote from the inner peripheral surface of the rotational drum 13. Inthis state, when the molten metal injected from the nozzle 16, isquenched for solidification in the cooling liquid 14 to start producingthe wire-like solidified body 17, the winding reel 19 is moved to theposition shown in phantom lines in FIG. 3. On the other hand, a portionof the wire-like solidified body 17 produced in the manner describedabove rides over the holder element 20.

When the winding reel 19 is moved as described above, the holder element20 is attracted to the winding peripheral surface 18; thus, as shown inFIG. 4, when the holder element 20 passes close by the windingperipheral surface 18, it is attracted to the winding peripheral surface18. In response thereto, the wire-like solidified body 17, as carried onthe holder element 20, is fixed to the winding peripheral surface 18.

As shown in FIG. 4, when the portion of the wire-like solidified body 17adjacent the front end thereof is fixed to the winding peripheralsurface 18, with the fixed portion serving as the winding starting endthe wire-like solidified body 17 is wound on the winding peripheralsurface 18, the wire-like solidified body 17 obtained being continuouslywithdrawn by the winding reel 19, as shown in FIG. 5.

In addition, in the embodiment shown in FIGS. 3 to 5, a plurality ofholder elements corresponding to holder element 20 may be distributed onthe inner peripheral surface fo the rotational drum 13. This arrangementwill make it possible to use a portion of the wire-like solidified body17 which is closer to its front end as the winding starting end and tofix the wire-like solidified body 17 more reliably to the windingperipheral surface 18.

Further, the holder element 20 may be at least partly embedded in asuitable recess formed on the inner peripheral surface of the drum 13.In this manner, by imposing a kind of restraint on the holder element 20to prevent it from moving in the direction of rotation of the drum 13while allowing it to move toward the winding peripheral surface 18, theholder element 20 can be prevented from sliding during the time when thedrum 13 is being accelerated.

In both of the embodiments shown in FIGS. 1 and 2 and in FIGS. 3 to 5,the holder elements 11 and 20 are made of a permanent magnet and thewinding peripheral surfaces 9 and 18 are made of a ferromagneticmaterial, such as an iron-type material. However, as shown in FIG. 6 tobe presently described, this relation may be reversed so that the holderelement is made of a ferromagnetic material while the winding peripheralsurface is made of a magnet.

Referring to FIG. 6, a rotational drum 22 to be used is open at oppositeends and is formed on its inner peripheral surface with a groove 24 forholding a cooling liquid 23 which is centrifugally formed into a layer.In the interior of the rotational drum 22, a winding reel 25 isdisposed, for example, at the same position as that of the winding reel19 shown in FIG. 4. The rotational drum 22, when seen on its innerperipheral surface, is rotated in the direction of arrow 26 while thewinding reel 25 is rotated in the same direction as the direction ofrotation of the rotational drum 22, as shown by an arrow 27, and isgiven substantially the same peripheral speed.

A nozzle 28 shown in phantom lines is disposed, inside the rotationaldrum 22 for example, at the same position as that of the nozzle 16 ofFIG. 3.

This embodiment is characterized in that a magnet 29 is provided at aleftward position on the winding peripheral surface 25a of the windingreel 25. One such magnet may be used as shown or a plurality of suchmagnets may be circumferentially distributed. The magnet 29 is made of apermanent magnetic material.

In this embodiment, a magnetically effective holder element 30 shown indotted, is sunk in a cooling liquid 23. The holder element 30 is made ofa ferromagnetic material, such as an iron-type material. In thisembodiment, a fine wire, i.e., wire-like solidified body is produced andthen withdrawn by the following procedure.

First, the rotational drum 22 and winding reel 25 are rotated atpredetermined speeds. Then, the holder element 30 is placed at aposition remote from a position adjacent the winding reel 25, on theinner peripheral surface of the drum 22, for preventing the holderelement 30 from being attracted to the winding peripheral surface 25abefore it has arrest the wire-like solidified body. Before the holderelement 30 placed in the manner described above, reaches the positionadjacent the winding reel 25 as the rotational drum 22 is rotated, amolten material (not shown) is injected. Such molten material isquenched for solidification by entering the cooling liquid 23, thusforming a wire-like solidified body 31 which then rides on the holderelement 30. The wire-like solidified body 31 is conveyed together withthe holder element 30 in the direction of arrow 26, and the holderelement 30 approaches the magnet 29 until there is more than apredetermined amount of magnetic force exerted therebetween, whereuponthe holder element 30 is attracted to the winding peripheral surface andthe wire-like solidified body 31 and is fixed on the winding peripheralsurface 25a. Therefore, as the winding reel 25 is rotated, the wire-likesolidified body 30 is wound on the winding reel 25.

In addition, in the initial stage of the production of the wire-likesolidified body 31, the nozzle 28 is at a leftward position as shown inFIG. 6, and thereafter it is gradually moved in the direction of arrow32. Therefore, the holder element 30 is placed at a leftward position onthe inner peripheral surface, as shown. Correspondingly thereto, theposition of the magnet 29 is selected, as described above.

The result of an experiment using the apparatus shown in FIG. 6 isdescribed below.

A1-1 % Si alloy was melted in the nozzle 28, the molten alloy wasinjected through the nozzle 28, and a wire-like solidified body 31 wasobtained in the cooling liquid 31. The diameter of the drum 22 was 600mm and that of the winding reel 25 was 200 mm; the rotational speed ofthe drum 22 was 260 rpm and that of the winding reel 25 was 720 rpm; theinjection pressure of argon gas was 1.8 kg/cm² ; and the nozzle 28 wasmade of graphite and its orifice diameter was 0.25 mm. Further, themagnet 29 placed on the winding reel 25 had a magnetic flux density of3400 gauss; there were 18 such magnets arranged at equal intervalscircumferentially of the reel 25.

About 1 kg of said alloy was fed to the nozzles 26, and approximatelythe same amount of wire-like solidified body 31 was wound on the windingreel 25.

In the embodiment shown in FIG. 6 and in the embodiment shown in FIGS. 3to 5, to attract the holder element 20 or 30 to the winding peripheralsurface 18 or 25a, the magnetic force of the permanent magnet must betaken into consideration. The magnetic force should be such that theholder element 20 or 30 centrifugally retained on the inner peripheralsurface of the rotational drum 1 or 22, is attracted to the windingsurface 18 or 25a against the centrifugal force and the viscosityresistance of the cooling liquid 14 or 23. For example, the aforesaidexperiment conducted in connection with the apparatus shown in FIG. 6indicated that the magnetic flux density of the magnet 29 was sufficientit it was greater than 2000 gauss.

In each of the embodiments described above, the magnetic force forattracting the holder element to the winding peripheral surface has beena permanent magnet. Thus, the attractive force due to the magnetic forceacts between the winding peripheral surface and the holder element allthe time and its has been necessary to attract the holder element to thewinding peripheral surface only when the long-sized object to bewithdrawn is present between the winding peripheral surface and theholder element. To this end, there has been employed a magneticattraction control means for selectively reducing the distance betweenthe winding peripheral surface 9 or 18 and the holder element 11 or 20(FIGS. 1 and 2 and FIGS. 3, 4 and 5) or for adjusting the timing forplacing the holder element 30 on the inner peripheral surface of therotational drum 22. However, if the magnetic force for attracting theholder element to the winding peripheral surface is provided by anelectromagnet adapted to be switched on or off, a switch for on-offcontrol of said electromagnet can serve as the magnetic attractioncontrol means.

For example, in the apparatus shown in FIG. 6, if the magnet 29 iscomposed of an electromagnet, then when the holder element 30 with thewire-like solidified body 31 carried thereon approaches the windingperipheral surface 25a, the holder element 30 with the wire-likesolidified body 31 firmly arrested thereby, is attracted to the windingperipheral surface 25a as shown as the electromagnet is turned on.

The above is equally true of the embodiment shown in FIGS. 1 and 2. InFIGS. 1 and 2, if at least a portion of the winding peripheral surface 9is made of an electromagnet, it is possible to attract the holderelement 11 to the winding peripheral surface 9 with the required timingwithout having to use such a moving means as the pantograph 10.

In the embodiment shown in FIGS. 1 and 2 and the embodiment shown inFIGS. 3 to 5, the winding peripheral surface 9 or 18 may be made of anelectromagnet, which is maintained turned on while employing thearrangement for moving the winding peripheral surface 9 or 18 and theholder element 11 or 20 toward each other.

The winding peripheral surface which rotates for winding the elongatedobject is not limited to a cylindrical peripheral surface represented bya winding drum or winding reel but may be an oblong peripheral surfacesuch as a belt entrained around two parallel rollers.

This invention is widely applicable to the withdrawal of elongatedobjects such as thin films, thin ribbons and fine wires of metals,alloys, amorphous materials and organic or inorganaic ceramic materials,including the aforesaid tape-like and wire-like solidified objectsobtained by quenching for solidification.

We claim:
 1. A method of continuously withdrawing an elongated productout of a melt, comprising the following steps:(a) forming a layer ofcooling liquid on an inner peripheral surface of a drum by rotating saiddrum about a drum axis, (b) providing in said rotatable drum a windingreel having an outer peripheral winding surface and a reel axisextending in parallel to and off-center relative to said drum axis, (c)rotating said winding reel in the same direction as said drum, (d)placing a magnetically effective holder element capable of beingmagnetically attracted to said winding surface of said winding reel, onsaid inner peripheral surface of said drum, whereby said magneticallyeffective holder element is initially retained by centrifugal force onsaid inner peripheral surface of said rotating drum until saidmagnetically effective holder element comes sufficiently close to saidwinding surface of said winding reel, (e) projecting said melt through anozzle into said layer of cooling liquid for forming and solidifyingsaid elongated product by quenching, (f) positioning a leading end ofsaid elongated product on said magnetically effective holder element fortransporting said leading end of said elongated product onto saidwinding surface of said winding reel, (g) bringing, by the rotation ofsaid drum, said magnetically effective holder element with the leadingend of said elongated product placed thereon, sufficiently close to saidwinding surface of said winding reel to cause a magnetic attractionbetween said magnetically effective holder element and said windingsurface of said winding reel for transferring said magneticallyeffective holder element and said leading end of said elongated productagainst said centrifugal force onto said winding surface of said windingreel, (h) securing said leading end of said elongated product to saidwinding surface of said winding reel by a magnetic force between saidmagnetically effective holder element and said winding surface of saidwinding reel, and (i) continuously withdrawing said elongated productfrom said melt by maintaining the rotation of said drum and of saidwinding reel.
 2. The method of claim 1 comprising making said holderelement (11, 20) of a permanent magnet, and making at least a portion ofsaid winding peripheral surface (9, 18) of said winding reel of aferromagnetic material for cooperation with said permanent magnet. 3.The method of claim 1 comprising making said holder element (30) of aferromagnetic material, and making at least a portion of said windingperipheral surface (25a) of said winding reel of a magnet forcooperation with said ferromagnetic material.
 4. The method of claim 1wherein said step of placing locates said holder element at a positionon the inner peripheral surface of said drum sufficiently remote from aposition adjacent said winding reel to prevent attraction at the time ofplacing, and wherein said step of positioning a leading end is performedbefore said holder element reaches the position adjacent said windingreel where attraction between said holder element and said winding reeltakes place.
 5. The method of claim 1 wherein causing said magneticattraction between said holder element and said winding surface of saidwinding reel, includes moving said winding reel (19) toward the innerperipheral surface of said drum.
 6. The method of claim 1 comprisingproviding said magnetic attraction and said magnetic force by anelectromagnet that can be switched on and off.
 7. The method of claim 6further including the step of turningon said electromagnet when saidholder element is sufficiently close to said winding surface of saidwinding reel for said transferring.
 8. An apparatus for continuouslywithdrawing an elongated product out of a melt, comprising a coolingdrum rotatably mounted for maintaining a layer of cooling liquid on aninner peripheral surface of said drum when said drum is rotating about adrum axis, a winding reel having an outer peripheral winding surface,said winding reel being mounted inside said cooling drum on a reel axisextending in parallel to and off-center relative to said cooling drumaxis for rotation in the same direction as said cooling drum, amagnetically effective holder element capable of being magneticallyattracted to said winding surface of said winding reel, saidmagnetically effective holder element being initially retained on saidinner peripheral surface of said cooling drum by centrifugal force whensaid cooling drum is rotating, nozzle means located inside said coolingdrum for directing a stream of said melt into said layer of coolingliquid for solidifying said stream by quenching to form said elongatedproduct, whereby a leading end of said elongated product is positionedon said magnetically effective holder element for transporting saidleading end onto said winding surface of said winding reel, and magneticmeans on or in said winding surface of said winding reel for attractingsaid magnetically effective holder element with said magneticallyeffective holder element passes by sufficiently close to said windingreel for transferring said magnetically effective holder element andsaid leading end onto said winding surface against said centrifugalforce, said magnetic means securing said magnetically effective holderelement and thereby also said leading end to said winding surface for acontinuous withdrawing operation as long as said cooling drum and saidwinding reel are rotating.
 9. The apparatus of claim 8 wherein saidwinding peripheral surface has a peripheral speed substantially the sameas that of said inner peripheral surface of said cooling drum.
 10. Theapparatus of claim 8 further comprising magnetic attraction controlmeans for controlling a magnetic force of said magnetic means so thatsaid magnetic force is sufficient to secure said magnetically effectiveholder element to said winding peripheral surface when said leading endis present between said winding peripheral surface and said holderelement.
 11. The apparatus of claim 10 wherein a magnetic attractionforce is permanently effective between said winding peripheral surfaceand said magnetically effective holder element, and wherein saidmagnetic attraction control means comprise means for reducing a distancebetween said winding peripheral surface and said magnetically effectiveholder element for transferring said magnetically effective holderelement from said inner peripheral surface of said cooling drum to saidwinding surface of said winding reel.
 12. The apparatus of claim 11wherein said magnetic means of said winding peripheral surface comprisea least a portion of said winding reel made of a ferromagnetic material,and wherein said holder element is made of a permanent magneticmaterial.
 13. The apparatus of claim 11 wherein at least a portion ofsaid winding peripheral surface forms a magnet, and said magneticallyeffective holder element is made of a ferromagnetic material.
 14. Theapparatus of claim 10 wherein at least a portion of said windingperipheral surface forms an electromagnet, and said magnetic attractioncontrol means has switch means for on-off controlling saidelectromagnet.